You'd also probably have to at least to some degree integrate the idea that it's 'okay' (not correct, just acceptable) to be irrational into your general thought process, to avoid unintentional signaling that you think poorly of them. If anything, irrational people are more likely to notice such subtle signals, since so much of their communication is based on them.
Or, you could just treat the existence of irrationality as a mere fact, like the fact that water freezes or runs downhill. Facts are not a matter of correctness or acceptability, they just are.
In fact (no pun intended), assigning "should-ness" to facts or their opposites in our brains is a significant force in our own irrationality. To say that people "should" be rational is like saying that water "should" run uphill - it says more about your value system than about the thing supposedly being pointed to.
Functionally, beliefs about "should" and "should not" assign aversive consequences to current reality - if I say water "should" run uphill, then I am saying that is is bad that it does not. The practical result of this is to incur an aversive emotional response every time I am exposed to the fact that water runs downhill -- a response which does not benefit me in any way.
A saner, E-prime-like translation of "water should run uphill" might be, "I would prefer that water ran uphill". My preference is just as unlikely to be met in that case, but I do not experience any aversion to the fact that reality does not currently match my preference. And I can still experience a positive emotional response from, say, crafting nice fountains that pump water uphill.
It seems to me that a rationalist would experience better results in life if he or she did not experience aversive emotions from exposure to common facts... such as the fact that human beings run on hardware that's poorly designed for rationality.
Without such aversions, it would be unnecessary to craft complex strategies to avoid signaling them to others. And, equally important, having aversive responses to impersonal facts is a strong driver of motivated reasoning that's hard to detect in ourselves!
Good summary; the confusion of treating natural mindless phenomena with intentional stance was addressed in the Three Fallacies of Teleology post.
When it is possible to change the situation, emotion directed the right way acts as reinforcement signal, and helps to learn the correct behavior (and generally to focus on figuring out a way of improving the situation). Attaching the right amount of right emotions to the right situations is an indispensable tool, good for efficiency and comfort.
A currently existing social norm basically says that everyone has the right to an opinion on anything, no matter how little they happen to know about the subject.
But what if we had a social norm saying that by default, people do not have the right to an opinion on anything? To earn such a right, they ought to have familiarized themselves on the topic. The familiarization wouldn't necessarily have to be anything very deep, but on the topic of e.g. controversial political issues, they'd have to have read at least a few books' worth of material discussing the question (preferrably material from both sides of the political fence). In scientific questions where one needed more advanced knowledge, you ought to at least have studied the field somewhat. Extensive personal experience on a subject would also be a way to become qualified, even if you hadn't studied the issue academically.
The purpose of this would be to enforce epistemic hygiene. Conversations on things such as public policy are frequently overwhelmed by loud declarations of opinion from people who, quite honestly, don't know anything on the subject they have a strong opinion on. If we had in place a social norm demanding an adequate amount of background knowledge on the topic before anyone voiced an opinion they expected to be taken seriously, the signal/noise ratio might be somewhat improved. This kind of a social norm does seem to already be somewhat in place in many scientific communities, but it'd do good to spread it to the general public.
At the same time, there are several caveats. As I am myself a strong advocate on freedom of speech, I find it important to note that this must remain a *social* norm, not a government-advocated one or anything that is in any way codified into law. Also, the standards must not be set *too* high - even amateurs should be able to engage in the conversation, provided that they know at least the basics. Likewise, one must be careful that the principle isn't abused, with "you don't have a right to have an opinion on this" being a generic argument used to dismiss any opposing claims.